Field of the Invention
The present invention relates to telecommunications, and in particular relates to a method of selecting a SIM for a location service and a multi-SIM device utilizing the same.
Description of the Related Art
It is often desirable, and sometimes necessary, to know the location of a terminal such as a mobile phone. The Secure User Plane Location (SUPL) specifications produced by the Open Mobile Alliance (OMA) are an IP based protocol for Assisted GPS to receive information of GPS satellites quickly via IP instead of slowly receiving over GPS satellite signaling. The SUPL specifications allow applications on a mobile phone to obtain the geographic location thereof. Currently, two versions of SUPL are defined in OMA specifications—SUPL version 1.0. SUPL 1.0 supports many positioning methods but provides only basic location capabilities using 2G or 3G cell identifiers (ID). SUPL 2.0, on the other hand, contains many more location capabilities including support for periodic, triggered and historic location, providing more precise location information using 4G cell IDs. It is possible that future versions of SUPL will eventually be developed that would support even more location services.
A multi-SIM (subscriber identity module) device, including particularly mobile phones, personal digital assistants, tablet and laptop computers, mobile WiFi router and mobile USB dongle can hold two or more SIM cards. Hereinafter “SIM” and “SIM card” will be used interchangeably. The multi-SIM device allows a user to operate with a corresponding number of communications networks and/or arrangements without the need to carry two or more wireless devices. Each SIM contains a unique international mobile subscriber identity (IMSI) and can subscribe to a communications network which supports a particular SUPL version, or even not any SUPL version. Because the multi-SIM device contains multiple SIMs, a method of automatic selecting a SIM for delivering location services is required.